120 research outputs found
Factores multiplicadores del río Tunjuelo
(Eng) The most important sources of pollution in urban rivers are the sewage system discharges, disturbing
the quality and behavior patterns of water resources. The Tunjuelo River is one of the most polluted and
important stream from Bogota city, receiving numerous wastewater discharges. Therefore, its sanitation
has become one of the main objectives of the environmental authority. However, in order to take action
is necessary to understand the water quality behavior specifically loads patterns. This article shows the
results of the load multiplier factors for total suspended solids (TSS) and biochemical oxygen demand
(BOD), these factors were calculated to understand the behavior of wastewater discharges and at different
points on the river. Finally, each discharge has its own characteristics that affect differently the behavior
of the river downstream, resulting in a distortion in the flow pattern in most of the sampled points.(Spa) Las fuentes puntuales de contaminación más importantes en los ríos urbanos son las descargas directas
del sistema de alcantarillado, además estas afectan la calidad y el patrón de comportamiento de las fuentes
hídricas. El río Tunjuelo es una de las corrientes de agua más importante y contaminada de la ciudad de
Bogotá, pues recibe una gran cantidad de vertimientos. Por lo anterior su saneamiento se ha convertido
en uno de los principales objetivos de la autoridad ambiental, sin embargo, para poder tomar acciones es
necesario entender su comportamiento. En el presente artículo se muestran los resultados de los factores
multiplicadores de carga para sólidos suspendidos totales (SST) y demanda bioquímica de oxígeno
(DBO), puesto que estos son el instrumento económico para el cálculo de la tasa retributiva en Colombia,
los cuales fueron calculados para entender el comportamiento de las descargas de aguas residuales y el
de diferentes puntos sobre el río. Finalmente, se puede observar que cada descarga tiene características
propias que afectan de diferente manera el comportamiento del río aguas abajo, generando como resultado
una distorsión en el patrón de flujo de los factores multiplicadores en la mayoría de puntos muestreados
Countries Response for People With Disabilities During the COVID-19 Pandemic
Background and ObjectivesDuring the Coronavirus disease 19 (COVID-19) pandemic, isolation and prevention measures to reduce COVID-19 contagions are essential for the care of all people; these measures should comply with the principles of inclusion and accessibility for people with disabilities (PWD), with all kinds of deficiencies and levels of dependency. Thereby, the aim of this article is to present the measures adopted for PWD or people with rehabilitation needs, for containment, mitigation, or suppression of the SARS-CoV-2 virus in different countries of all continents and of all income levels.MethodsA narrative approach was used in this article. First, a broad search was carried out in the 193 member states of the UN, and then 98 countries that issued any document, report, or information related to disability and COVID-19 were selected. Finally, 32 countries were included in this article because they presented official information. We considered official sources, the information available in the government, or on the health ministry page of the country. In this way, the countries that presented information which did not correspond to an official source were excluded. The search was conducted in August 2020 and updated in March 2021.ResultsFirst, the non-pharmacological general interventions for PWD included informative measures and general recommendations during the stay at home, isolation, and biosecurity measures, contagion prevention, detection of positive cases, mobilization measures, and measures implemented in institutions or residences of PWD. Second, we identified the economic and social benefits provided to PWD during the pandemic. Finally, we identified the measures taken by countries according to the type of impairment (visual, hearing, physical, mental, and cardiopulmonary impairment) during the COVID-19 pandemic.ConclusionIn response to the COVID-19 pandemic, only 50% of countries from the five world regions created and implemented specific measures for PWD to containment, mitigation, or suppression of the SARS-CoV-2 virus. There is very little specific information available about the measures to continue with the care of people with rehabilitation needs and the long-term follow-up of PWD, and for the prevention and response to violence, especially for women with disabilities
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Identification of a novel locus on chromosome 2q13, which predisposes to clinical vertebral fractures independently of bone density.
OBJECTIVES: To identify genetic determinants of susceptibility to clinical vertebral fractures, which is an important complication of osteoporosis. METHODS: Here we conduct a genome-wide association study in 1553 postmenopausal women with clinical vertebral fractures and 4340 controls, with a two-stage replication involving 1028 cases and 3762 controls. Potentially causal variants were identified using expression quantitative trait loci (eQTL) data from transiliac bone biopsies and bioinformatic studies. RESULTS: A locus tagged by rs10190845 was identified on chromosome 2q13, which was significantly associated with clinical vertebral fracture (P=1.04×10-9) with a large effect size (OR 1.74, 95% CI 1.06 to 2.6). Bioinformatic analysis of this locus identified several potentially functional SNPs that are associated with expression of the positional candidate genes TTL (tubulin tyrosine ligase) and SLC20A1 (solute carrier family 20 member 1). Three other suggestive loci were identified on chromosomes 1p31, 11q12 and 15q11. All these loci were novel and had not previously been associated with bone mineral density or clinical fractures. CONCLUSION: We have identified a novel genetic variant that is associated with clinical vertebral fractures by mechanisms that are independent of BMD. Further studies are now in progress to validate this association and evaluate the underlying mechanism
Extraction of the Muon Signals Recorded with the Surface Detector of the Pierre Auger Observatory Using Recurrent Neural Networks
We present a method based on the use of Recurrent Neural Networks to extract the muon component from the time traces registered with water-Cherenkov detector (WCD) stations of the Surface Detector of the Pierre Auger Observatory. The design of the WCDs does not allow to separate the contribution of muons to the time traces obtained from the WCDs from those of photons, electrons and positrons for all events. Separating the muon and electromagnetic components is crucial for the determination of the nature of the primary cosmic rays and properties of the hadronic interactions at ultra-high energies.
We trained a neural network to extract the muon and the electromagnetic components from the WCD traces using a large set of simulated air showers, with around 450 000 simulated events. For training and evaluating the performance of the neural network, simulated events with energies between 1018.5, eV and 1020 eV and zenith angles below 60 degrees were used. We also study the performance of this method on experimental data of the Pierre Auger Observatory and show that our predicted muon lateral distributions agree with the parameterizations obtained by the AGASA collaboration
A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality
The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (X) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of X with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy
Study on multi-ELVES in the Pierre Auger Observatory
Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity
- …